1) Fractionation of fibrinolytically active components of blood and tissue was carried out. 2) There are two kinds of proactivators in the normal human plasma, proactivator A and proactivator B. 3) Fibrinolytic components of blood may probably be dissociated to a smaller particle in urea solution, and the smaller one is yet fibrinolytically active. 4) The amount of proactivator A in purified plasminogen is very small, which may be removed during the purification procedures. The authors wish to express their hearty thanks to Prof, S. Okamoto, Kobe University, for his advice and kind discussions.
New method for determination of blood fibrinolytic activity of patient with skin disease by means of gel filtration was discussed. Each one case of urticaria acuta, fibrinolytic purpura and pemphigus vulgaris showed marked fibrinolytic activity (streptokinase-activated lysis) on a standard plate. The results of the experiments suggested that proactivator should be given much attention in some dermatoses. Parts of this paper have been presented at the 14th Annual Congress of The Japanese Society of Allergy on Nov., 20, 1964 in Nagoya. The assistance of the staff of Department of Physiology, School of Medicine, Keio University, is gratefully acknowledged.
A distinct increase in blood plasma iron content was caused in animals after administration of L-histidine or its near-ultraviolet irradiated modification. Using partially purified enzyme system from rat liver homogenate, release of iron from ferritin was observed, when L-histidine or urocanic acid was added as a substrate. n-Histidine, L-glutamic acid, imidazole, 2-imidazolidone (ethy-leneurea), imidazole-4, 5-dicarboxylic acid or histamine-2HCI had no effect on iron release. It has been assumed that the origin of the increased plasma iron caused by L-histidine is ferritin iron of the liver and that ferritin iron acts as an electron acceptor coupled with dehydrogenation by the xanthine oxidase in the course of metabolism of L-histidine.